Transmitter.



Rax.

W. E. MCCORMIGK. TRANSMITTER. APPLzcuroN funn JUNE is, 1905.

Patented 12h25, 1910.

the construction iliistrated in F ig.

in the appended claims.

j .sniffiis igiinnir onrion.

WILLIAM E. Mc i OBBI'CK, 0F CHICAGO, ILLINOIS, ASSIGNQR TO INTERNATIONALTELE- .rnonn ma. ILLINOIS. l

f fammes med :une 19,

Tall inkom it may concern:

Be it known that L'WiLLiAM E. McConi lucir, a citizen of the UnitedStates,resid ing at Chicago, in the county of Cook and State oflllinois,'liaveinvented certain neviy and useful Improvements inTransmitters, of which the -following is a speciication,. referencebeing li'adtherein tol-the accom- This invention .relatestbiin'iprovements in telephone transmitters of that.character in whichcarbon Grot-herresistancevarying substance is located between the twoelectrades with which Jthe line connections are in circuit.. l i y Theinvention consists of the combina tionsand arrangements of partshereinafter particularly described and then pointed ont Referring to'the accompanying drawings-Figure Al is'a sectional elevation of atransmitter embodying my inventiong' Fig. Q is a section on the line 2 2of Fig.` 1; Fig. 3 is arear elevationivith'the cap and bridge removed;Figli is a' detail side elevation of thediaphragm,damping spring, carboncup a'ndV the securing' device therefor in disassembled relationg'Fig. 5is a side view partially iii elevation showing a modiiication of theinvent-ion; Fi G is a perspective view ol the modified irm of dampingspring; and Fie 7 isa sectional View of 5 with the parte separated.

Referring to the drawings, 10 indicates the usual frame which may beofany suitable forin and 'is provided with the usual mouth piece 11. -Aninclosiiw case or capA l2 of suitable forni is secure( in any -preferredmanner to a rearward annular flange 13 of the frame 10. A support orbridge 14 is secured as by screws l5 to thel flange L3 at oppositepoints and is provided with an opening 16 intermediate its ends Vinwhich is located a bush-in 17 which may be insu-V lated from the bri ge14 as shown. A nut. 18 screwing upon the. front threaded end of thebushin 17 serves to secure the latter in position, athough it. isobvious that .the bushing may be secured in place by heading over itsfront end. A post '19 extends into the bushing 1'( and is adapted to beheld in adjusted position, in the usua1 manner of TRANSMITTER.

VSpecification of Letters mirentJ Patented Jan. 25, 1910.

1905. 'seriai No. 265,839.

such devices, by a set screw 20.' This post i9 carries an electrodelwhich preferably is, gold plated and is located or projects into the cup22 containing granular carbon'.

or other resistance varying substance, and is insulated from such cup bythe supple# vIi'iental diaphragm :'24 of mica or other suit- `ablematerial which may be secured tothe .electrode 21 in any suitablenianner.- The cnj 22 may be. of an suitable construction, an in theconstruction illustrated in Figs. l. and 4, itcomprises a body 25 havingat Vits end adjacent tlie electrode. 2l 'an in- Werdl;v extendingannular tlanfre 26 between which and a ring '2 the niica diaphragm :2lis clamped. The ring 2 is adapted to frictionally engage the cup andmayhave an internal insulating-strip ofpaper or other material, as at28, insulating the carbon 23 from the cup. The band is provided at theend opposite the flange 26 with :in outwardly extending .flan e 29,' thepurpose of which will be hereina-ter explained.

Bet. 'een the cup 92 andthe diaphragm 30,

wliich is seated in the depression in the 'frame 10 formed b v the longe13 and provided wilh the usual insulating and damping rin 3l, thedamping device 32 is located. This damping device is so constructed thatin addi;ion to providing one of the, electrodes 'of the transmitter itis arranged to eilectually prevent excessive vibration of the diaphragmwhile at the same time the instrument is rendered exceedingly sensitive,and uniformity of vibration, `that is to say the vibration of thediaphragm as a unit, is msured. 'This damping device may be made ofslieet'metal. such as steel, of suitable elasticity or resiliency, andin the present embodiment of the invention it comprises a dat central orbody portion 33, which is in contact with the diaphragm 30. The area ofthe body portion 'of the damping device is at least as large as theopening of the cup 22 so as to entirely close the .same and pre- -ventspilling of the carbon; this central por: l

tion forms the. other electrode of ,the trans mitter and isV preferablygold plated for that purpose.' The damping device is provided with aplurality of spring arms 34, two of such arms being shown in the presentembcdiinent 'of tbe invention. These arms 34 extend toward the rear ofthe transmitter nation with a iaphragm, a bridge having a air* of postsprovided with cavities, a carcnn-containing cup, an electrode carried bythe bridge, a supplemental diaphragm Se-V -eured to the electrode and tothe cup, and a.

damping spring having a central portion closing the'cu and engaging thediaphragm and forming t xe other electrode, and having a pair of springarms the ends of which are seated Vin the cavities ofthe posts on thebridge. A Y

1 1. In a tele hone transmitter, the combifv nat-ion with a 'aihragmandV a. carbon oonrtanning cup, of emping spring, and means for securingth'ei'diaphragm, cup and damping spring together independently of thetransmitter ranle.

12.' In s, tele iidne transmitter, the combination with a ighragm, and acarbon-con taining cui) having a ange, o a damping spring hav a. Centralportion closing the cup and a pan' of spring arms, and a retaining ringhafinr lingers pari-sing through the diaphragm an engaging the flange ofthe cup to secure the cup against the daxnping spring.

In testimon whereof I aix my signature in presence o two witnesses.

WILLIAM E. MCCORMICK. Witmess:

' ARTHUR B. SEIBOLD,

ELIZABETH MoLn-on.

